From 20c000492fd45fa91762adad8e6cc322107c18ec Mon Sep 17 00:00:00 2001
From: Trammell Hudson <hudson@osresearch.net>
Date: Sun, 3 May 2015 15:12:01 -0400
Subject: [PATCH] project 3d into 3d (broken?)

---
 stl_3d.c | 24 ++++++++++++++++++++++++
 stl_3d.h |  6 ++++++
 2 files changed, 30 insertions(+)

diff --git a/stl_3d.c b/stl_3d.c
index ce94f9b..8bdda53 100644
--- a/stl_3d.c
+++ b/stl_3d.c
@@ -468,3 +468,27 @@ refframe_inset(
 	*x_out = *y_out = 0;
 	fprintf(stderr, "inset failed 2\n");
 }
+
+
+v3_t
+refframe_project(
+	const refframe_t * const ref,
+	const v3_t p
+)
+{
+	v3_t o = { 0, 0, 0 };
+	o.p[0] = 0
+		+ ref->x.p[0] * p.p[0]
+		+ ref->y.p[0] * p.p[1]
+		+ ref->x.p[0] * p.p[2];
+	o.p[1] = 0
+		+ ref->x.p[1] * p.p[0]
+		+ ref->y.p[1] * p.p[1]
+		+ ref->z.p[1] * p.p[2];
+	o.p[2] = 0
+		+ ref->x.p[2] * p.p[0]
+		+ ref->y.p[2] * p.p[1]
+		+ ref->z.p[2] * p.p[2];
+
+	return o;
+}
diff --git a/stl_3d.h b/stl_3d.h
index b6e47ef..b9a56fe 100644
--- a/stl_3d.h
+++ b/stl_3d.h
@@ -102,5 +102,11 @@ v3_project(
 	double * const y_out
 );
 
+/** Project a point in a reference frame back into 3D */
+v3_t
+refframe_project(
+	const refframe_t * const ref,
+	const v3_t p
+);
 
 #endif